GROWING GOURMET - Anto2ni.it

318 GROWTH PARAMETERS
Form of Product Sold to Market: Fresh and dried mushrooms. Waste straw substrate has been test
marketed as a cattle feed.
Nutritional Content: Crude protein: 10-30%. Vitamins C: 30-144 mg/i00 g; Niacin: 109 mgIlOOg;
Folic Acid: 65 mgIlOO g. High in potassium: 306 mg/100 g. For further information, see Bano &
Rajarathnam (1982), Miles & Chang (1986), andRai et al. (1988).
Medicinal Properties: Recent studies (Gunde-Cimerifian et al., 1995) show that Pleumtus ostreatus
and other closely related species naturally produce
Lovastatin ®
zyme A reductase), a drug approved by the FDA in 1987 for treating excessive blood cholesterol.
More Lovastatin is present in the caps than in the stems, more
concentrated on the mature gills, and
especially in the spores. This
compound and others related to it may explain the often reported cholesterol-lowering
effects of many woodland mushrooms.
When mice were implanted
with Sarcoma 180, the tumors were inhibited by more than 60% after
one month. (Ying, 1987.) The Oyster mushrooms constituted 20% of their daily diet. Oyster mushrooms
figure as a relatively minor player, comparatively, in the realm of medicinal mushrooms.
Anecdotal reports suggest this mushroom improves liver and kidney function and helps gastrointestinal
disorders. According to Singer (1986), the sclerotia of a related, tropical species, Pleurotus
tuber-regium (Fr.) Singer is used by native peoples for such diverse medicinal purposes as stomach
pain, constipation, fever, blood pressure and even smallpox.* (Singer (1986) and Oso (1977)).
Allergic reactions to the spores of P ostreatus are commonly
reported by workers picking mushrooms
indoors. Symptoms include fever, headache, congestion, coughing, sneezing, nausea, &
general malaise. Workers who, at first, can tolerate contact with Oyster spores, often develop increased
sensitivity with continued exposure. Filtration masks help but do not entirely solve this
work-place related problem. The question as to whether or not spores of Oyster mushrooms can carry
virus harmful to humans has not yet been satisfactorily answered. Few individuals are allergic to Oyster
mushrooms after they have been cooked. For more information, consult Reshef et al. (1988).
Flavor, Preparation & Cooking: Stir-fry in a light oil at high heat until golden brown and then
cooked with other condiments.
Comments: The Oyster mushrooms are the easiest to grow. Disadvantages of their cultivation are in
their short shelf life post harvest and the health problems posed by the prolific spore load generated
within the confines of the growing room.
Cold and warm weather strains of this mushroom are widely in use. The above-described temperatures
for initiating P. ostreatus are based on cold weather strains. Strains evolving in warm
geographical niches behave more in accordance with the parameters outlined for Pleurotus
pulmonarius. (See page 321.)
Pleurotus ostreatus is an extraordinarily interesting mushroom from many viewpoints. Highly tolerant
and responsive to carbon dioxide levels, Zadrazil (1974) noted that mycelial growth peaks at
280,000 ppm or 28% CO2. Unless CO2 levels are reduced to less than 1000 ppm (.01%), noticeable
* For information on the cultivation of Pleurotus tuber-regiurn, consult Okhuoya et al. (1988 & 1990) and Omoanghe
(1992). SeeFigure43.
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